The present invention relates to a composition or concentrate for preserving wood and wood materials at least one insecticide or insecticide mixture, at least one solvent or solvent mixture, a binder or binder mixture and, optionally, a fungicide or fungicide mixture, processing aid and/or additive, dye, pigment, dye mixture or pigment mixture, in which the composition contains a defined proportion of specific insecticides or insecticide mixtures.
The chemical compounds 2,2-dimethyl-3-dichlorovinyl-cis/trans-cyclopropanecarboxylic acid .alpha.-cyano-3'-phenoxy-4'-fluorobenzyl ester or cyano-(4-fluoro-3-phenoxyphenyl)-methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate (C.A.) and (-)1R-trans-2,2-dimethyl-3-(2,2-dichlorovinyl)-cyclopropanecarboxylic acid pentafluorobenzyl ester or (pentafluorophenyl)-methyl 1R,3R-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate (C.A.) or enantiomeric compounds thereof are already known as insecticides (cf. German Offenlegungsschrift No. 2,709,264).
These compounds are insecticides having high contact-insecticidal activity. If attempts are made to use these insecticides as wood preservatives with solvents or diluents, the result, for example at a concentration of 0.05% by weight, on contact of the beetle species Sitophilus granarius with the treated surface is a destruction quota of 100% after 5 hours. Since useful insects can thus also be killed or endangered by overflows from the treated surfaces or on contact with the treated surface, the use of these insecticides as wood preservatives has hitherto been avoided. Furthermore, there is the additional disadvantage that the said insecticides, namely pentafluorobenzyl 1R-trans-2,2-dimethyl-3-(2,2-dichlorovinyl)-cyclopropanecarboxylate or (pentafluorophenyl)-methyl 1R,3R-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate, sometimes suffer a reduction in activity after aging and/or exposure to the weather.